1. Field of the Invention
With regard to the classification of art, this invention is believed to be found in the general class entitled "Valves and Valve Actuation" and more particularly to those subclasses pertaining to rotary butterfly valves that are used to control the flow of particulate articles without damage to the articles.
2. Description of Related Art
Butterfly valves are known in the prior art. Two examples of the known prior art are U.S. Pat. No. 5,236,003 that issued to Habicht on Aug. 17, 1993, and U.S. Pat. No. 5,388,807 that issued to Habicht on Feb. 14, 1995. U.S. Pat. Nos. 5,236,003 and 5,388,807 are solely owned by the present inventor.
U.S. Pat. Nos. 5,236,003 and 5,388,807 have been successfully used in many material handling applications. The quick coupling and modular design has resulted in the use of these valves at the discharge or delivery end of hoppers, bins and the like, that hold flowable dry granular materials. It has been found that the modular features of U.S. Pat. Nos. 5,236,003 and 5,388,807 have many advantages in the pharmaceutical and food industries. The easy disassembly and thorough cleaning features of each of these valves have led to attempts the use of these valves in process applications for controlling the flow of fragile particulate articles such as tablets, capsules and the like. One disadvantage of these valves when used with fragile particulate articles is breakage or damage to the articles. It has been found that particulate articles are broken in the cited prior art valves dudng the closing of the valve.
It therefore has been determined that a low profile valve is required which is capable of easy disassembly, cleaning, and reassembly. It is also very important that the needed valve be capable of feeding particulate articles without breakage. The needed valve must also meet the cleanliness validation requirements of agencies, that monitor the pharmaceutical, and food industries.
The present invention solves the identified needs that are described above.